David urquhart and frank wynne



(No Model.)

D. URQUHART 8: P. WYNNE.

ELECTRIC RAILWAY.

No. 591,706. Patented Oct. 12.1897.

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I m g P UNITED STATES PATENT O FICE.

DAVID URQUHART AND FRANK WYNNE, OF LONDON, ENGLAND.

ELECTRIC RAILWAY.

SPECIFICATION forming part of Letters Patent No. 591,706, dated October 12, 1897.

i g u fil d November 17, 1896. Serial No. 612,457. (No model.)

To all whom it may concern/.-

Be it known that we, DAVID URQUHART and 'FRANK WYNNE, subjects of the Queen of Great Britain and Ireland, residing at Westminster, London, England, have invented Improvements in Electric Railways, of which the following is a specification.

This invention has reference to electric tramways and railways in which the electric energy required is generated at a fixed point or points and conducted to the motor on the vehicle to be electrically propelled (hereinafter called the car) by means of fixed insulated conductors and a series of suitablyinsulated short contact-surfaces exposed in the roadway and hereinafter called roadcontacts, such road-contacts being automatically connected by some suitable switch de- Vice to the electrical main when the car is over or nearly over them and automatically disconnected from such main when the vehicle has passed them, the car being provided with a brush or collector which rubs on the road-contacts, thus connecting the drivingmotor to the electric main. Usually an electromagnet is employed to actuate the switch which is to connect the road-contact over which the vehicle may for the time being be situated to the electric main, this electromagnet when energized attracting an armature or keeper which by its motion closes the switch against the force of gravity or against a spring, or both, so that on the electromagnet ceasing to pull the switch will antomatically open and disconnect the road contact from the electric main, as well understood. In all cases where the electroma net which actuates the switch has a winding carrying the main current it may happen under certain conditions that there will be sufficient leakage from the road-contact just left to the road-contact ahead to keep the ma net-armature attracted, thus preventing the switch from automatically opening; and this invention has for its object to obviate this disadvantage. For this purpose, according to one arrangement, we place a conducting bar or plate, (hereinafter called a guardplate,) preferably sunk in the roadway, in the center of the gap between consecutive road-contacts, and connect it to the main conductor through the switch of a trailing roadcontact, a second or pull-down electromagnet being inserted in the connecting-lead, so that any leakage-current that may flow will then pass principally round this pull-down electromagnet and insure the opening of the switch.

Figure 1 of the accompanying drawings shows, diagram matioally, one arrangement of this kind applied in connection with means or apparatus of the kind herein referred to for electrically connecting a motor on a car to an insulated main conductor. Fig. 2 is a cross -section showing, diagrammatically, a modified arrangement. Figs. 3 and 4 are respectively a side elevation and plan showing, diagrammatically, another modification; and Fig. 5 is a plan showing a further modification.

, Referring to Fig. 1, 1 l are insulated roadcontacts in the form of short bars arranged longitudinally of the roadway and each adapted to be placed in'electrical connection at the proper time with an insulated main conductor 2 through the winding 3 of an electromagnet 4 and a conductor 5 by a spring or gravity switch-lever 6, which forms an armature to the electromagnet and carries an insulated contact-piece 6*, which bears, when the switch-lever is attracted, against contacts 3 and 5 on the normally free ends of the winding 3 and conductor 5, respectively, the said switch-lever automatically moving away from such contacts when the circuit of the electromagnet is broken, as well understood.

7 7 are conducting guard-plates each placed in the gap between the ends of successive road-contacts 1, preferably sunk in the roadway below the level thereof and connected by a conductor 8 to the main conductor 2 through the switch ofthe adjacent trailing road-contactthat is to say, the switch of the road-contact to the rear of it. In the example shown the conductor 8 is connected to the conductor or winding 3 of the trailing road-contact at a point betweenthe correesponding electromagnet 4E and the contact 3%,

and included in it is an electromagnet 9, ar-,

ranged below the switch-lever 6, which forms an armature to it.

10 is the car-contact brush arranged to travel on the road-contacts l and connected to one pole of the car-motor 10, the other oif leakage from it.

pole of which is connected to a contact 10 in connection with an earth-action conductor E. With the arrangement described a leakage-current passing round the winding of the electromagnet 9 will energize this magnet and cause it to pull down the switch-lever 6 and break the circuit between the corresponding road-contact and the main conductor 2. Under certain conditions there may also be sufficient leakage from the road-contacts 1 to earth to keep the switch, with main-current winding 3, closed. This we obviate by placing a metal bar or rail 11 on each side of each roadcontact, as shown in full lines in Fig. 2, these bars being connected to the main conductor 2 when the corresponding switch is closed, but through the winding of the pull-down magnet 9, as in Fig. 1, and not through the winding of the switch-magnet.

Instead of twobars we sometimes place a curved plate or channeled bar round each roadcontact, but insulated therefrom, so as to cut Such a curved plate or channeled bar, which would inclose the roadcontact except on its upper surface, is inclicated by the full and dotted lines 11 11 in Fig.

2, the insulating material in which the roadeontact 1 is placed being indicated at 12. The channeled bars 11 11* may be used to carry the insulated main conductor 2, as indicated at 2. In each case the bar 7 or bars 11 or channel 11 11, as the case may be, will by the arrangement described be at about the same potential as the corresponding road-contact, so that no leakage-current can pass through or over the insulation 12,,and all leakage-current must take place from the bars '7 or 11 through the leads 8 and switch-contact 3, and will thus help to open the switch even if no pull-down electromagnets 9 be included in the leads. Each bar 7, placed between two consecutive road-contacts, as in Fig. 1, may be formed with a side projection '7, so-placed, as shown, for example, in Figs. 3 and 4, that the car-contact brush 10, which in this case will be provided with a short lateral extension, shall touch it after leaving the roadcontact to the rear of it, thus insuring the passage of'a momentary current through the pull-down magnet 9 corresponding to'such road-contact and the disconnection of such road-contact from the main conductor. Such additional forward side projections 7 might obviously be combined with guard-rails or a channel-bar arranged at the sides of or surrounding the next rearward road-contact, as shown, for example, in plan in Fig.5, where it is represented as connected to a channeled bar 11 11, surrounding the rearward roadcontact.

We have described our invention as applied to cars carrying a relatively short collecting brush or brushes rubbing on relatively long road-contacts, or,- it may be, groups of road-contacts, the contacts in each group being electrically connected together; but our invention can be equally applied to cars provided with a long contact bar or'brush rubbing on short studs or plates placed in the roadway. Any known or suitable means may be used for energizing the electromagnets of the switches in succession as the vehicle to be propelled travels along the track.

What we claim is- 1. In apparatus of the kind herein referred to for supplying electricity to electrically-propelled vehicles, the combination with roadcontacts, a main conductor, and electromagnetic devices or switches for successively placin g said road-contacts in connection with said main conductor, of conducting guard plates or rails located in proximity to the road-contacts and adapted'to be connected to the main conductor by the switch of the corresponding road-contact and to be then placed in parallel with the electromagnetic winding of the said switch substantially as described for the purpose specified.

2. In apparatus of the kind herein referred to for supplying electricity to electrically-propelled vehicles, the combination with roadcontacts, a main conductor, andelectromagnetic devices or switches for successively placin g said road-contacts in connection with said main conductor, of conducting guard plates or rails located in proximity to the road-contacts and each connected to. a conductor adapted to be placed by the switch of the corresponding road-contact in direct connection with said main conductor when said switch is closed, and electromagnetic devices arranged in the conductors connected to the guard plates or rails and each adapted when excited to open or assist in opening the corresponding switch, substantially as described,

3. In apparatus of the kind herein referred to for supplying electricity to electrically-propelled vehicles, the combination with roadcontacts, a main conductor, and electromagnetic devices or switches for successively placing said road-contacts in connection with said main conductor, of conducting guard plates or rails and connected leads arranged in parallel with said switches, and adapted to be directly connected with said main conductor when the corresponding switch is closed and electromagnetic devices included in said leads and adapted when energized to open the cor-- therefrom, and leads connected to said chan-.

Y neled bars and adapted to be placed in direct connection with said main conductor when the corresponding switch is closed, substantially as described. a

5. In apparatus of the kind herein referred to for supplying electricity to electrically-pro pelled vehicles, the combination with roadcontacts, a main conductor, and electromagnetic devices or switches for successively placing said road-contac ts in connection with said main conductor, of channeled bars surrounding said road-contacts but insulated therefrom, leads connected to said channeled bars and adapted to be placed in direct connection with said main conductor when the corresponding switch is closed, and electromagnetic devices arranged in said leads and adapted when energized to open or assist in opening said switches, substantially as described.

6. The combination with road-contacts 1, a main conductor 2, and switches each comprising a magnet-winding 3 connected with a road-contact and with a contact 3 a magnetcore 4: on which said winding is coiled, a conductor 5 connected with said main conductor and with a contact 5 and a switch-lever serving as an armature to said magnetcore and adapted when in its closed position to electrically connect said contacts 3 and 5, of channeled bars 11, 11 containing insulating material in which said road-contacts are embedded, leads 8 connected with the winding 3 between the corresponding cores 4 and contacts 3", and electromagnets 9 arranged in the leads 8 and adapted to assist in the open ing of the corresponding switch-levers, substantially as described for the purpose specified.

7. The combination with road-contacts, a main conductor, and switches adapted to suecessively place said road-contacts in connection with said main conductor of channeled bars 11, 11 containing insulating material in which said road-contacts are embedded, leads 8 connected with the winding 8 between the corresponding cores 4 and contacts 3,electromagnets 9 arranged in the leads 8 and adapted to assist in the opening of the corresponding switch-levers, and forward projections 7' exposed in the roadway, each of said projections being arranged in proximity to a road-contact and connected with thechanneled bar of the road-contact to the rear of it, substantially as described for the purpose specified.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

Witnesses:

JAMES M. SMALL, WVM. HATES. 

